I. Field of the Invention
The present invention relates generally to the compound:    N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide,also referred to herein as RTA 408, 63415, or PP415. The present invention also relates to polymorphic forms thereof, methods for preparation and use thereof, pharmaceutical compositions thereof, and kits and articles of manufacture thereof.
II. Description of Related Art
The anti-inflammatory and anti-proliferative activity of the naturally occurring triterpenoid, oleanolic acid, has been improved by chemical modifications. For example, 2-cyano-3,12-diooxooleana-1,9(11)-dien-28-oic acid (CDDO) and related compounds have been developed. See Honda et al., 1997; Honda et al., 1998; Honda et al., 1999; Honda et al., 2000a; Honda et al., 2000b; Honda et al., 2002; Suh et al., 1998; Suh et al., 1999; Place et al., 2003; Liby et al., 2005; and U.S. Pat. Nos. 8,129,429, 7,915,402, 8,124,799, and 7,943,778, all of which are incorporated herein by reference. The methyl ester, bardoxolone methyl (CDDO-Me), has been evaluated in phase II and III clinical trials for the treatment and prevention of diabetic nephropathy and chronic kidney disease. See Pergola et al., 2011, which is incorporated herein by reference.
Synthetic triterpenoid analogs of oleanolic acid have also been shown to be inhibitors of cellular inflammatory processes, such as the induction by IFN-γ of inducible nitric oxide synthase (iNOS) and of COX-2 in mouse macrophages. See Honda et al, (2000a), Honda et al. (2000b), Honda et al. (2002), and U.S. Pat. Nos. 8,129,429, 7,915,402, 8,124,799, and 7,943,778, which are all incorporated herein by reference. Compounds derived from oleanolic acid have been shown to affect the function of multiple protein targets and thereby modulate the activity of several important cellular signaling pathways related to oxidative stress, cell cycle control, and inflammation (e.g., Dinkova-Kostova et al., 2005; Ahmad et al., 2006; Ahmad et al., 2008; Liby et al., 2007a, and U.S. Pat. Nos. 8,129,429, 7,915,402, 8,124,799, and 7,943,778).
Given that the biological activity profiles of known triterpenoid derivatives vary, and in view of the wide variety of diseases that may be treated or prevented with compounds having potent antioxidant and anti-inflammatory effects, and the high degree of unmet medical need represented within this variety of diseases, it is desirable to synthesize new compounds with different biological activity profiles for the treatment or prevention of one or more indications.